The present technology relates to an optical apparatus, and a projection apparatus.
In a projector (a projection apparatus) that is one image display device, a discharge lamp is widely used as a light source and a transmission-type liquid crystal element or a DMD (Digital Micromirror Device) is widely used as an image modulation element. Also, a device and an optical component have been enhanced. Further, in recent years, a projection-type image display device using a higher resolution reflection-type liquid crystal panel (a reflection-type optical modulation element) has also been put into practical use.
Brightness of an image to be displayed are important elements in gaining an advantage in the projector market. When a light amount of a light source increases to brighten an image to be displayed by a projector, temperatures of parts on an optical path rise. The rise in temperature of the parts on the optical path causes an error in an optical positional relationship due to a difference in linear expansion coefficient between constituent parts and causes degradation of image quality of a projected image such as a change in focus position of the projected image or a change in projection position.
For this reason, as a heat solution for a projector, for example, a waveplate adhered to a PS conversion element (an optical device) for aligning a polarization direction of light with a predetermined polarization direction may he formed of a quartz member usable in a higher temperature environment.    [Patent Literature 1] Japanese Patent Laid-Open Publication No. 2009-20240